Devices and Methods for Facilitating Dmrs Sequence Grouping

1. A method of wireless communication, comprising: obtaining information for a transmission scheduled with pi/2 BPSK modulation, wherein the transmission includes two or more demodulation reference signal (DMRS) symbols; determining a plurality of DMRS sequences for the transmission, the plurality of DMRS sequences comprising a respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols, wherein each DMRS sequence subsequent to another DMRS sequence of the plurality of DMRS sequences is dependent on its immediately preceding DMRS sequence, and wherein an initial DMRS sequence of the plurality of DMRS sequences is determined independently of any other respective DMRS sequence of the plurality of DMRS sequences; and sending the transmission including each respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols.

2. The method of claim 1 , wherein the two or more DMRS symbols each include a length less than 30.

3. The method of claim 2 , wherein determining the plurality of DMRS sequences for the transmission comprises: determining the respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols from a DMRS grouping table, wherein each DMRS sequence subsequent to another DMRS sequence in the DMRS grouping table is dependent on its immediately preceding DMRS sequence.

4. The method of claim 3 , wherein the DMRS grouping table is associated with a particular number of DMRS symbols.

5. The method of claim 1 , wherein: determining the plurality of DMRS sequences for the transmission comprises: generating a Gold sequence; segmenting the generated Gold sequence into different segments; and sending the transmission comprises sending each segment of the Gold sequence in different DMRS symbols.

6. The method of claim 5 , wherein each segment of the Gold sequence includes a length less than 30.

7. The method of claim 1 , wherein: the transmission scheduled with pi/2 BPSK modulation is further scheduled to employ frequency hopping, including a first group of two or more DMRS symbols in a first frequency and a second group of two or more DMRS symbols in a second frequency; and determining the plurality of DMRS sequences for the transmission comprises: determining a first respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols in the first group, wherein each DMRS sequence subsequent to another DMRS sequence is dependent on its immediately preceding DMRS sequence in the first group, and determining a second respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols in the second group, wherein a DMRS sequence for a first DMRS symbol in the second group is independent of any DMRS sequence for the first group, and wherein each DMRS sequence in the second group subsequent to another DMRS sequence in the second group is dependent on its immediately preceding DMRS sequence in the second group.

8. The method of claim 1 , wherein: the transmission scheduled with pi/2 BPSK modulation is further scheduled to employ transmission bundling including repeating the transmission across multiple slots with a first group of two or more symbols scheduled for a DMRS in a first slot and a second group of two or more DMRS symbols in a second slot; and determining the plurality of DMRS sequences for the transmission comprises: determining a first respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols in the first group, wherein each DMRS sequence subsequent to another DMRS sequence is dependent on its immediately preceding DMRS sequence in the first group, and determining a second respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols in the second group, wherein a DMRS sequence for a first DMRS symbol in the second group is dependent on a DMRS sequence for a last DMRS symbol of the first group, and wherein each DMRS sequence in the second group subsequent to another DMRS sequence in the second group is dependent on its immediately preceding DMRS sequence in the second group.

9. The method of claim 1 , wherein: the determining the plurality of DMRS sequences for the transmission comprises determining the respective DMRS sequence for each DMRS symbol of the two or more DMRS symbols from a first DMRS grouping table of a plurality of DMRS grouping tables; the first DMRS grouping table is for a first quantity of DMRS symbols; and a second DMRS grouping table of the plurality of DMRS grouping tables is for a second quantity of DMRS symbols that is different from the first quantity of DMRS symbols.

10. A wireless communication device, comprising: a transceiver; a memory; and a processing circuit communicatively coupled to the transceiver and the memory, the processing circuit and the memory configured to: obtain information for a transmission scheduled with pi/2 BPSK modulation, wherein the transmission includes two or more symbols scheduled for a demodulation reference signal (DMRS), determine a plurality of DMRS sequences for the transmission, the plurality of DMRS sequences comprising a respective DMRS sequence for each symbol of the two or more symbols scheduled for a DMRS, wherein each DMRS sequence subsequent to another DMRS sequence of the plurality of DMRS sequences is dependent on its immediately preceding DMRS sequence, and wherein an initial DMRS sequence of the plurality of DMRS sequences is determined independently of any other respective DMRS sequence of the plurality of DMRS sequences, and transmit, via the transceiver, the transmission including each respective DMRS sequence for each DMRS symbol of the two or more symbols scheduled for the DMRS.

11. The wireless communication device of claim 10 , wherein the two or more symbols scheduled for a DMRS each include a length less than 30.

12. The wireless communication device of claim 11 , wherein the determining the plurality of DMRS sequences for the transmission comprises: determining the respective DMRS sequence for each symbol of the two or more symbols scheduled for the DMRS from a DMRS grouping table, wherein each DMRS sequence subsequent to another DMRS sequence in the DMRS grouping table is dependent on its immediately preceding DMRS sequence.

13. The wireless communication device of claim 12 , wherein the DMRS grouping table is associated with a particular DMRS length.

14. The wireless communication device of claim 12 , wherein the DMRS grouping table is associated with a particular number of symbols scheduled for a DMRS.

15. The wireless communication device of claim 10 , wherein: the determining the plurality of DMRS sequences for the transmission comprises generating a Gold sequence, and segmenting the generated Gold sequence into different segments; and the transmitting the transmission including each respective DMRS sequence for each DMRS symbol of the two or more symbols scheduled for the DMRS comprises transmitting each segment of the Gold sequence in different symbols scheduled for a DMRS.

16. The wireless communication device of claim 10 , wherein the transmission scheduled with pi/2 BPSK modulation is further scheduled to employ frequency hopping, including a first group of two or more symbols scheduled for a DMRS in a first frequency and a second group of two or more symbols scheduled for a DMRS in a second frequency; and wherein the plurality of DMRS sequences for the transmission comprises: determining a first respective DMRS sequence for each symbol of the two or more symbols scheduled for a DMRS in the first group, wherein each DMRS sequence subsequent to another DMRS sequence is dependent on its immediately preceding DMRS sequence in the first group; and determining a second respective DMRS sequence for each symbol of the two or more symbols scheduled for a DMRS in the second group, wherein a DMRS sequence for a first symbol scheduled for a DMRS in the second group is independent of any DMRS sequence for the first group, and wherein each DMRS sequence in the second group subsequent to another DMRS sequence in the second group is dependent on its immediately preceding DMRS sequence in the second group.

17. The wireless communication device of claim 10 , wherein the transmission scheduled with pi/2 BPSK modulation is further scheduled to employ transmission bundling including repeating the transmission across multiple slots with a first group of two or more symbols scheduled for a DMRS in a first slot and a second group of two or more symbols scheduled for a DMRS in a second slot; and wherein the plurality of DMRS sequences for the transmission comprises: determining a first respective DMRS sequence for each symbol of the two or more symbols scheduled for a DMRS in the first group, wherein each DMRS sequence subsequent to another DMRS sequence is dependent on its immediately preceding DMRS sequence in the first group; and determining a second respective DMRS sequence for each symbol of the two or more symbols scheduled for a DMRS in the second group, wherein a DMRS sequence for a first symbol scheduled for a DMRS in the second group is dependent on a DMRS sequence for a last symbol scheduled for a DMRS of the first group, and wherein each DMRS sequence in the second group subsequent to another DMRS sequence in the second group is dependent on its immediately preceding DMRS sequence in the second group.

18. A method of wireless communication at a first wireless communication device, comprising: sending a first transmission to schedule a second transmission from a second wireless communication device with pi/2 BPSK modulation, wherein the second transmission is scheduled to include two or more demodulation reference signal (DMRS) symbols; and receiving the scheduled second transmission including the two or more DMRS symbols, wherein at least one DMRS symbol of the two or more DMRS symbols includes a DMRS sequence based on its immediately preceding DMRS sequence, and wherein a first DMRS symbol of the two or more DMRS symbols includes a DMRS sequence that is determined independently of any other DMRS sequence of the two or more DMRS symbols.

19. The method of claim 18 , wherein the DMRS sequence based on its immediately preceding DMRS sequence is defined by a DMRS grouping table that indicates a respective DMRS sequence for each subsequent DMRS symbol based on a corresponding DMRS sequence for any immediately preceding DMRS symbol.

20. The method of claim 19 , further comprising: sending the DMRS grouping table to the second wireless communication device.

21. The method of claim 19 , further comprising: sending a sequence start indicator to the second wireless communication device, the sequence start indicator configured to identify a starting sequence in the DMRS grouping table for the first DMRS symbol of the two or more DMRS symbols.

22. The method of claim 19 , wherein the DMRS grouping table is associated with a particular DMRS length.

23. The method of claim 19 , wherein the DMRS grouping table is associated with a particular number of DMRS symbols.

24. The method of claim 18 , wherein each DMRS symbol of the two or more DMRS symbols includes a segment of a Gold sequence.

25. A first wireless communication device, comprising: a transceiver; a memory; and a processing circuit communicatively coupled to the transceiver and the memory, the processing circuit and the memory configured to: send a first transmission via the transceiver to schedule a second transmission from a second wireless communication device with pi/2 BPSK modulation, wherein the second transmission is scheduled to include two or more symbols with a demodulation reference signal (DMRS), and receive the scheduled second transmission including the two or more symbols scheduled for a DMRS, wherein at least one symbol of the two or more DMRS symbols includes a DMRS sequence based on its immediately preceding DMRS sequence, and wherein a first DMRS symbol of the two or more DMRS symbols includes a DMRS sequence that is determined independently of any other DMRS sequence of the two or more symbols.

26. The first wireless communication device of claim 25 , wherein the DMRS sequence based on its immediately preceding DMRS sequence is defined by a grouping table that indicates a respective DMRS sequence for each subsequent symbol scheduled for a DMRS based on a corresponding DMRS sequence for any immediately preceding symbol scheduled for a DMRS.

27. The first wireless communication device of claim 26 , wherein the processing circuit and the memory are further configured to: send the grouping table to the second wireless communication device.

28. The first wireless communication device of claim 26 , wherein the processing circuit and the memory are further configured to: send a sequence start indicator to the second wireless communication device, the sequence start indicator configured to identify a starting sequence in the grouping table for the first symbol of the two or more symbols.

29. The first wireless communication device of claim 26 , wherein the grouping table is associated with at least one of a particular DMRS length or a particular number of symbols scheduled for a DMRS.

30. The first wireless communication device of claim 25 , wherein each symbol of the two or more symbols scheduled for a DMRS includes a segment of a Gold sequence.